Recently there has been a lot of talk in the surf world about “green” wetsuits (1, 2, 3, 4). Most of the claims revolve around the use of neoprene made from limestone rather than petroleum. I asked Todd Copeland, who works on Patagonia's Fabric Development team, to shed some light on these claims.
Many of us at Patagonia wear wetsuits but until 2005 none of us had ever developed one. When we first sought to get into the business, we went to visit the raw material manufacturers to learn how neoprene is made, what kinds of materials are available, and their relative advantages and drawbacks, including environmental.
A wetsuit is basically made of foamed rubber, sometimes called a sponge. It can be laminated on one or two sides to fabric, usually polyester or nylon in a jersey knit. The pieces are glued and/or stitched together to make a wetsuit, and then the seams can be sealed to prevent water leakage.
The sponge is made from polychloroprene rubber chips, commonly called neoprene. These are melted and mixed together with foaming (blowing) agents and pigment, usually carbon black, and baked in an oven to make it expand.
To make the polychloroprene chips, the manufacturer polymerizeschloroprene monomers, which means reacting small molecules together toproduce the large macromolecules (polymers) that make up rubber. Thereare two methods of manufacturing chloroprene monomer. The most commonmethod – Method 1 – takes butadiene through a two-step process ofchlorination and subsequent dehydrochlorination. The butadiene forMethod 1 is derived from petroleum. The less commonly used method is todimerize acetylene (react 2 acetylene molecules together to form adouble molecule) and then hydrochlorinate the dimer. The acetylene forthis Method 2 is derived from limestone.
Most people can imagine the environmental impacts of somethingderived from petroleum. Like gasoline and most synthetic chemicals, theorigins of butadiene for making chloroprene via Method 1 start with oilexploration and drilling. Then the crude must be transported. (Imagesof the Trans-Alaska Pipeline, the Exxon Valdez, and birds dying in oilspills come to mind.) At the refinery, components of crude oil arebroken apart and separated to make different organic compounds,including butadiene.
The environmental impacts of something derived from limestone,however, are unfamiliar. Like oil, limestone is a limited, nonrenewableresource that is extracted from the earth. Limestone rock is mined frommountains, and requires diesel-powered equipment such as cranes,backhoes, and dump trucks the size of houses. The crushed limestone isfed into a furnace and heated to extremely high temperatures (over3600º F) in an energy-intensive process. From the furnace, componentsare reacted with other chemicals to make products such as acetylenegas.
Chloroprenes derived from either petroleum or limestone arechemically equivalent. Polymerized and made into chips, limestone-basedpolychloroprene is not inherently stronger or more flexible thanpetroleum-based polychloroprene nor does it insulate better. Anyadvantage of one fabric or another relies on differences inmanufacturing methods used to create the sponge.
Patagonia uses limestone-based polychloroprene for most of itsneoprene products. Reducing dependence on oil and oil-derived chemicalsis important. However, the trade-off in this case involves mining,pollution from diesel fuel combustion, and high energy usage. We havedrawn the conclusion that both versions of polychloroprene have equallysignificant environmental impacts, although limestone definitely hasthe advantage of being easier than oil to clean up in the case of aspill!
Polychloroprene from any raw-material source creates the greaterpart of a wetsuit’s environmental impact; the other components such asnylon or polyester fabric play a much smaller role. We have reduced theenvironmental impact of our wetsuits by using recycled polyester andchlorine-free wool in the lining. These materials are moreenvironmentally friendly than virgin polyester or chlorine-treatedwool, respectively. The biggest environmental gain, however, isefficiency: the wool grid lining allows us to use a thinner layer ofneoprene without sacrificing warmth retention. For example, Patagonia’s3-mm suit is as warm as a typical 3/4, reducing the amount ofpolychloroprene in the wetsuit and, proportionately, its environmentalimpact.
One way to further “green” a wetsuit would be to focus on theadhesives in both the lamination and gluing processes. Solvents used inthese processes evaporate into the air during manufacturing, pollutingthe environment with VOCs (volatile organic compounds). Converting tonontoxic, more environmentally friendly methods of laminating fabric toneoprene and gluing cut pieces would greatly reduce a wetsuit’senvironmental footprint.
I’m glad to see that surfers are interested in buying and using“green” wetsuits. But don’t settle for marketing “greenwash!” Limestonedoesn’t make a wetsuit more environmentally friendly. Push for new,innovative materials and construction methods, because we’ve got a longway to go before anyone has a true “green” wetsuit.
Update 8/21/13: We've come a long way. This fall, we'll be releasing the first batch of Patagonia Wetsuits made with Yulex biorubber derived from the guayule plant. It's the beginning of our shift away from traditional, non-renewable neoprenes. Watch this video to learn more.
[Yulex Wetsuits – From Seed To Suit. Video: Patagonia]